diff --git a/app.py b/app.py
index 6f5fd04..9981ed3 100644
--- a/app.py
+++ b/app.py
@@ -557,10 +557,8 @@ def outbox_detail(item_id):
         abort(404)
 
     if doc["meta"].get("deleted", False):
-        obj = ap.parse_activity(doc["activity"])
-        resp = jsonify(**obj.get_tombstone().to_dict())
-        resp.status_code = 410
-        return resp
+        abort(404)
+
     return jsonify(**activity_from_doc(doc))
 
 
@@ -574,10 +572,7 @@ def outbox_activity(item_id):
 
     obj = activity_from_doc(data)
     if data["meta"].get("deleted", False):
-        obj = ap.parse_activity(data["activity"])
-        resp = jsonify(**obj.get_object().get_tombstone().to_dict())
-        resp.status_code = 410
-        return resp
+        abort(404)
 
     if obj["type"] != ActivityType.CREATE.value:
         abort(404)
diff --git a/blueprints/admin.py b/blueprints/admin.py
index e390aaa..94204bf 100644
--- a/blueprints/admin.py
+++ b/blueprints/admin.py
@@ -68,7 +68,7 @@ def admin_logout() -> _Response:
 @noindex
 def admin_login() -> _Response:
     if session.get("logged_in") is True:
-        return redirect(url_for("admin_notifications"))
+        return redirect(url_for("admin.admin_notifications"))
 
     devices = [doc["device"] for doc in DB.u2f.find()]
     u2f_enabled = True if devices else False
@@ -80,7 +80,7 @@ def admin_login() -> _Response:
             if verify_pass(pwd):
                 session["logged_in"] = True
                 return redirect(
-                    request.args.get("redirect") or url_for("admin_notifications")
+                    request.args.get("redirect") or url_for("admin.admin_notifications")
                 )
             else:
                 abort(403)
@@ -98,7 +98,7 @@ def admin_login() -> _Response:
 
             session["logged_in"] = True
             return redirect(
-                request.args.get("redirect") or url_for("admin_notifications")
+                request.args.get("redirect") or url_for("admin.admin_notifications")
             )
         else:
             abort(401)
diff --git a/core/activitypub.py b/core/activitypub.py
index b5cf1d9..442d461 100644
--- a/core/activitypub.py
+++ b/core/activitypub.py
@@ -118,11 +118,13 @@ class MicroblogPubBackend(Backend):
         is_public = False
         if visibility in [ap.Visibility.PUBLIC, ap.Visibility.UNLISTED]:
             is_public = True
+
         object_id = None
         try:
             object_id = activity.get_object_id()
         except Exception:  # TODO(tsileo): should be ValueError, but replies trigger a KeyError on object
             pass
+
         object_visibility = None
         if activity.has_type(
             [ap.ActivityType.CREATE, ap.ActivityType.ANNOUNCE, ap.ActivityType.LIKE]
diff --git a/core/outbox.py b/core/outbox.py
index bc77a3b..dbff5c0 100644
--- a/core/outbox.py
+++ b/core/outbox.py
@@ -7,6 +7,7 @@ from typing import Dict
 from little_boxes import activitypub as ap
 
 from core.db import DB
+from core.db import find_one_activity
 from core.db import update_many_activities
 from core.shared import MY_PERSON
 from core.shared import back
@@ -26,18 +27,26 @@ def process_outbox(activity: ap.BaseActivity, new_meta: _NewMeta) -> None:
 @process_outbox.register
 def _delete_process_outbox(delete: ap.Delete, new_meta: _NewMeta) -> None:
     _logger.info(f"process_outbox activity={delete!r}")
-    obj = delete.get_object()
+    obj_id = delete.get_object_id()
 
+    # Flag everything referencing the deleted object as deleted (except the Delete activity itself)
     update_many_activities(
-        {"meta.object_id": obj.id}, {"$set": {"meta.deleted": True, "meta.undo": True}}
+        {"meta.object_id": obj_id, "remote_id": {"$ne": delete.id}},
+        {"$set": {"meta.deleted": True, "meta.undo": True}},
     )
 
-    in_reply_to = obj.get_in_reply_to()
-    if in_reply_to:
-        DB.activities.update_one(
-            {"activity.object.id": in_reply_to},
-            {"$inc": {"meta.count_reply": -1, "meta.count_direct_reply": -1}},
-        )
+    # If the deleted activity was in DB, decrease some threads-related counter
+    data = find_one_activity(
+        {"meta.object_id": obj_id, "type": ap.ActivityType.CREATE.value}
+    )
+    if data:
+        obj = ap.parse_activity(data["activity"])
+        in_reply_to = obj.get_in_reply_to()
+        if in_reply_to:
+            DB.activities.update_one(
+                {"activity.object.id": in_reply_to},
+                {"$inc": {"meta.count_reply": -1, "meta.count_direct_reply": -1}},
+            )
 
 
 @process_outbox.register
diff --git a/core/shared.py b/core/shared.py
index a424c01..98e2629 100644
--- a/core/shared.py
+++ b/core/shared.py
@@ -1,3 +1,4 @@
+import binascii
 import os
 from datetime import datetime
 from datetime import timezone
@@ -102,7 +103,7 @@ def post_to_outbox(activity: ap.BaseActivity) -> str:
         activity = activity.build_create()
 
     # Assign create a random ID
-    obj_id = back.random_object_id()
+    obj_id = binascii.hexlify(os.urandom(8)).decode("utf-8")
     uri = activity_url(obj_id)
     activity._data["id"] = uri
     if activity.has_type(ap.ActivityType.CREATE):
@@ -112,6 +113,7 @@ def post_to_outbox(activity: ap.BaseActivity) -> str:
         activity._data["object"]["url"] = urljoin(
             BASE_URL, url_for("note_by_id", note_id=obj_id)
         )
+        activity.reset_object_cache()
 
     back.save(Box.OUTBOX, activity)
     Tasks.cache_actor(activity.id)